1. Field of the Invention
The present invention relates to an electrical card connector having a stand-off device, and particularly to an electrical card connector which can shield a fastener, which is employed to mount the stand-off device to a printed circuit board, from interfering other electronic devices. This application relates to the contemporaneously filed two other applications having the same title, the same inventor and the same assignee with the invention.
2. Description of Related Art
Electrical card connectors, such as PCMCIA (Personal Computer Memory Card International Association) card connectors, are widely used in computer industry for electrically connecting with inserted electronic cards which function as removable mass storage devices. To meet the trend of miniaturization and high-speed data transmission of computer technology, the electrical card connectors are developed to have a compact and high-density arrangement regarding contacts of the electrical card connectors, which may result in EMI (Electromagnetic Interference) and ESD (Electro-static Discharge) problems, thereby adversely affecting electrical performance of the electrical card connectors.
In order to achieve better electrical performance, the electrical card connectors are equipped with grounding devices to ground the inserted electronic cards to a ground circuit of a printed circuit board on which the connectors are mounted. At the same time, the electrical card connectors often have stand-off devices for providing clearance between the connectors and the printed circuit board to thereby allowing components such as semiconductors to be mounted on the printed circuit board below the card connectors. Generally, the stand-off devices of the electrical card connectors also have grounding function. Thus, no additional grounding devices are required for the electrical card connectors. Examples of these conventional electrical card connectors are disclosed in U.S. Pat. Nos. 6,019,633, 6,231,382, 6,059,586 and 6,048,214.
Referring to FIGS. 5 and 6, a conventional electrical card connector 4 and a printed circuit board 5 on which the connector 4 is mounted are shown. The electrical connector 4 comprises an insulating body 40 in which a plurality of terminals 41 are provided for electrical connection to the printed circuit board 5, a shield 42 covering the insulating body 40 and a pair of stand-off devices 44 (only one is shown) attached to the shield 42 on opposite sides thereof. Each stand-off device 44 is generally of an L-shaped configuration including a retention portion 440 and a terminal portion 441 extending perpendicularly from a lower edge of the retention portion 440. The retention portion 440 defines a first and a second slits (not labeled) for fitly receiving therein a first spring tab 422 and a second spring tab 424 of the shield 42, respectively, whereby the stand-off device 44 is securely attached to the shield 42. The terminal portion 441 has a projection 442 defining a screw hole (not labeled) therein. A bolt 6 is employed to upwardly extend through a positioning hole 50 of the printed circuit board 5 and then into the screw hole of the stand-off device 44, thereby fixing the connector 4 on the printed circuit board 5. It is noted that the terminal portion 441 is also connected to a ground circuit of the printed circuit board 5 for grounding purpose.
The bolt 6 generally has a large lengthwise dimension for fixing the electrical card connector 4 to the printed circuit boards having various thickness. When the printed circuit board 5 is thinner, a tail portion 61 of the bolt 6 extends beyond the projection 442 and is mostly exposed above the printed circuit board 5. The exposed tail portion 61 of the bolt 6 has a risk of interfering other electronic devices, whereby a connection is easy to become loose between the connector 4 and the printed circuit board 5, which results in an unreliable electrical connection between the connector 4 and the printed circuit board 5. At the same time, the exposed tail portion 61 of the bolt 6 may scratch or even damage the electronic devices, thereby increasing the manufacturing cost.
Hence, an improved electrical card connector is required to overcome the disadvantages of the related art.
Accordingly, it is an object of the present invention to provide an electrical card connector having a stand-off device, the connector being configured to prevent a fastener, which is employed to mount the stand-off device to a printed circuit board, from interfering other electronic devices.
In order to achieve the object set forth, an electrical card connector in accordance with the present invention comprises an insulating body in which a plurality of terminals are provided for electrical connection to a printed circuit board, a shield covering the insulating body and a pair of stand-off devices attached on opposite sides of the shield. Each stand-off device includes a retention portion secured to the shield, a terminal portion with a hole defined therein extending laterally from a lower edge of the retention portion for connection to the printed circuit board and a shield member upwardly extending from edges of the terminal portion to form a shield space for shielding a bolt which engages with the hole terminal portion.